Multiple button, multiple function, mutiple value flash as3

Question

I want to make multiple button function with this function

for(var i=1; i <= 3; i++){this["btn"+i].addEventListener(MouseEvent.CLICK, someFunction);}

then, every i clicked some button, i want it to trace some number that exactly same with [i]. Lets say i clicked 'btn1' then it trace '1'. What should i do? Thankyou. Beginner at flash.

Answer 1

The key is knowing that event object, that is passed to subscribed methods also carries a reference to the source of the event.

function someFunction(e:Event):void
{
    // Get the reference to the button and access its name.
    var aButton:DisplayObject = e.currentTarget as DisplayObject;
    var aName:String = aButton.name;

    // If all the buttons are named in the way you put it:
    // Extract digits.
    var aDigits:String = aName.substr(3);

    // Convert them into number.
    var anIndex:int = int(aDigits);

    // Profit!
    trace(anIndex);
}

UPD. As Vesper pointed out below, it needs some explanation.

There are two references in the event object: e.target and e.currentTarget, that might or might not be the same:

• e.target is the original source of event
• e.currentTarget is the object you subscribed the event handler to

Let us think how MouseEvent.CLICK occurs. You click a button. At the same time you click a MovieClip/Sprite that contains the button. All their parents. Finally, Stage. So the e:MouseEvent starts at the button so the button dispatches it, then it bubbles (this process is called bubbling, read this: Event Bubbling, and Stop Propagation) one level up, then button parent fires the event, and so on all the way up to stage.

There are also 2 properties that can change the result of event handling:

• InteractiveObject.mouseEnabled allows or disallows the object to fire mouse events: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/InteractiveObject.html#mouseEnabled
• DisplayObjectContainer.mouseChildren allows or disallows the mouse to interact with the container's display children: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/DisplayObjectContainer.html#mouseChildren